本文通过对四川盆地元古宇-下古生界勘探最成功的两个地区--威远震旦系气田和资阳震旦系含气区天然气成藏要素和成藏过程的详细比较,得出 ①资阳含气区和威远气田的原始烃源相同,均是下寒武统生成的油裂解的天然气,不同的是资阳为残留的气顶气,威远是水溶气脱溶气.②资阳含气区和威远气田震旦系碳酸盐岩基质孔隙度相近,资阳地区溶蚀洞穴发育,但裂缝不发育,储层渗透性较差,非均质性强;威远地区储层洞穴不发育,但裂缝发育,形成统一的裂缝-孔洞系统.③威远地区具有统一的圈闭,闭合度高(800 m),闭合面积大(895 km2).资阳含气区不具有统一的圈闭,多为局部的小高点.④喜马拉雅期隆升作用使资阳统一含气区分散化和气藏变小,形成多压力系统的含气区;威远地区快速大幅度隆升, 溶于水中的天然气脱溶, 形成具同一压力系统的整装气田.⑤资阳含气区的成藏过程为 (资阳-威远)古油藏→原油裂解→气顶天然气→隆升调整→现今(残留)含气区,其天然气藏是隆升调整成藏,是在原古气藏的基础上改造残留而成;威远地区的成藏过程则是(资阳-威远)古油藏→原油裂解→天然气大量溶于水中→隆升使得带有大量天然气的水向威远运移和天然气脱溶→现今(新生)气藏,属天然气的脱溶成藏.资阳含气区受古构造的控制明显;威远气田则主要受今构造的制约.因此, 在四川盆地震旦系和下古生界的油气勘探中, 既要研究其古构造的特征和演化, 也要研究今构造的特征和分布规律, 才能发现不同类型的天然气藏.

8 m3/km2之间，具备形成大气田的气源条件。因此，研究区天然气来源具有原地性的特征，泊尔江海子断裂南部烃源岩优于北部烃源岩。]]>

8m3/km2,having the conditions of gas source for developing large gas field.In conclusion,the gas accumulation in study area is characteristic of generating in situ,and the quality of gas source rocks in the south of Boerjianghaizi fault is better than rocks in the north.]]>

为了揭示泊尔江海子断裂对鄂尔多斯盆地北部杭锦旗地区上古生界天然气成藏的控制作用，应用地震和钻井资料，在断裂活动性分析的基础上，根据断层泥比率和断层连通概率法对泊尔江海子断裂的侧向和垂向封闭性进行半定量评价，探讨断裂和天然气富集区的关系。结果表明：泊尔江海子断裂呈现3次明显的活动高峰期，分别为加里东期—早海西期的断裂形成期、印支期—早燕山期的挤压逆断裂活动期、中晚燕山期的走滑撕裂活动期，而中晚燕山期的走滑撕裂控制了上古生界天然气主要成藏期。断裂的封闭性具有“横向分段、纵向分层”的特点；横向上，以断层泥比率(SGR)等于0.3为界将泊尔江海子断裂分为侧向优势输导区和侧向封闭区；纵向上，在石千峰组和上石盒子组断裂启闭系数基本都小于1.0，断裂垂向封闭，在下石盒子组和山西组断裂启闭系数主要集中在4.0~10.0，断裂垂向开启。在断裂侧向优势输导区，断裂南部主力烃源区生成的天然气，经断裂发生垂向和侧向运移，易在断裂北部地区富集成藏；在侧向封闭区，则易在断裂南部地区富集成藏。

In order to reveal the control functions of Boerjianghaizi fault on natural gas accumulation of Upper Paleozoic in Hangjinqi block of the northern Ordos Basin, the history of the fault activity, the lateral and vertical sealing ability of the fault were studied by using fault growth index evolution, fault shale gouge ratio method and fault connectivity probability method through seismic and drilling data of this area. Then Boerjianghaizi fault effects on the natural gas enrichment zones were discussed. The results showed that Boerjianghaizi fault had three obvious peaks of activity in the history of evolution, which were Caledonian to Early Hercynian fracture period, Indosinian to Early Yanshanian squeezing thrust fault activity period, and Mid-late-Yanshanian strike-slip tearing activity period. Mid-late-Yanshanian strike-slip tearing activity period matched well with the main stage of gas accumulation of Upper Paleozoic. It was pointed out that sealing ability of Boerjianghaizi fault had the characteristics of “horizontal sectioning, vertical layering”. In the horizontal direction, Boerjianghaizi faults were divided into lateral migration fault areas and lateral sealed fault areas according to the shale gouge ratio (SGR) which equals to 0.3 as the dividing line. In the vertical direction , the fault plane was vertically sealed in Upper Shihezi and Shiqianfeng formations because the fault sealing coefficients were almost less than 1.0 in the section, while the fault plane was vertically open in Lower Shihezi and Shanxi formations because the fault sealing coefficients mostly range from 4.0 to 10.0 in the section. Meanwhile, in the lateral migration fault areas, natural gas generated from the main source areas which were in the south side of Boerjianghaizi fault was transmitted in the vertical and lateral direction through the fault, then natural gas accumulated in large amount in the north side of the fault easily, but in the lateral sealed fault areas, it is easy to find the natural gas pools in the south side of the fault.

中元古代长城纪华北克拉通南缘的大地构造背景一直备受关注。学者们主要依据该时期火成岩地球化学性质推断其构造背景,提出了B型俯冲、安第斯型俯冲、非造山环境以及与Columbia超大陆裂解有关的伸展环境。本次研究应用地球物理方法来剖析鄂尔多斯盆地中南部长城系构造格架和地层分布,以探索研究区大地构造背景及盆地属性。二维地震资料显示长城纪构造旋回包含裂陷期和裂后期。裂陷期半地堑主控边界断层活动强度大,下降盘发生旋转掀斜,发育次级地堑、半地堑,同时发育扇三角洲、水下扇沉积,楔状体沉积中心地层厚度大。裂后期断层活动减弱,水体范围扩大,地层超覆在早期楔状地层之上,地层厚度变化小。重力异常反演表明,研究区存在同期的凹陷和凸起,它们可能受控于边界断裂。结合地块周缘长城系沉积特征,我们认为鄂尔多斯地块中元古代长城纪盆地属性为陆内裂陷。

The tectonic setting of southern margin of North China Craton has drawn much attention during Mesoproterozoic Changcheng Period. Researchers have proposed several plausible models of geological settings mostly based on geochemical properties of volcanic rocks. The main views about the geological background are B-type subduction, Andean type subduction, non-orogenic extension and stretching which is related to the breakup of Supercontinent Columbia. This paper focus on tectonic features and stratum distribution of Changcheng Group in the south central Ordos block with geophysical methods meanwhile makes some study on its tectonic setting and basin property. The 2D seismic data indicates tectonic cycle in Changcheng Period with syn-rift and post-rift phase included. In syn-rift phase, the boundary faults act intensely, and the hanging wall rotated, leading to the development of sub-grabens and half-grabens. In the meantime fan delta and subaqueous fans filled in. The formations thicknesses are huge in depocenter of wedges. In post rift phase, the activity of faults was weak, resulting in the formation with consistent thickness, which overlapped on the wedges. Besides, the consequence of gravity anomaly inversion suggests several depressions and salients developed during the same period which were probably controlled by the boundary faults. Combined with the sedimentary characteristics of block margin, we deem the study area to be a rift basin during the Changcheng Period.

华北克拉通存在三个主要的中元古代裂谷带,从南到北分别为熊耳裂谷带、燕辽裂谷带以及渣尔泰-白云鄂博-化德裂谷带。其中熊耳群中火山岩的峰期年龄为1780~1750Ma,其上还有形成于被动大陆边缘的五佛山群、汝阳群以及官道口群。中北部的燕辽裂谷带包括长城系、蓟县系和青白口系,其中长城系团山子组和大红峪组火山岩的年龄分别为~1640Ma和1626~1622Ma,蓟县系高于庄组、雾迷山组和铁岭组凝灰岩的年龄分别为1560Ma、1485Ma和1437Ma,而下马岭组凝灰岩年龄为1366~1380Ma。北缘渣尔泰-白云鄂博-化德裂谷带中渣尔泰群书记沟组玄武岩年龄为1743Ma,阿古鲁沟组酸性火山岩年龄为~810Ma,白云鄂博群尖山组中基性火山岩年龄为1728Ma,化德群比鲁特组火山碎屑岩年龄为1515Ma。中元古代岩浆事件除了裂谷带中的火山作用外,还包括三期基性岩墙群(~1780Ma 太行-吕梁岩墙群、~1730Ma密云岩墙群和~1620Ma泰山岩墙群)以及1.76Ga到1.65Ga非造山岩浆组合(斜长岩-环斑花岗岩体-A型花岗岩)。中元古代中期,华北克拉通北缘发育了基性岩席(墙)、A型花岗岩以及碳酸岩脉,双峰式岩浆作用说明华北北缘在中元古代中期经历了裂谷作用,与哥伦比亚超大陆的最终裂解有关,并且与白云鄂博巨型REE-Nb-Fe矿床的形成具有成因上的联系。华北克拉通北部两个裂谷带中的地层具有可以对比的层序以及时代,而中元古代中期辉绿岩墙、A型花岗岩以及碳酸岩脉可以与其它克拉通同时期的非造山岩浆作用对比,证明华北克拉通经历了哥伦比亚超大陆的最终裂解。古地磁数据已经证明在哥伦比亚超大陆时期Siberia、Laurentia、Baltica、Amazion以及华北克拉通是连接在一起的,而北缘中元古代中期大陆裂谷相关岩浆岩的发现也说明它是与另一个古大陆相连的。华北克拉通南缘熊耳火山岩的构造背景到底是大陆裂谷还是大陆边缘弧则关系着其是与另一个克拉通相连还是面向大海,这需要我们进一步深入研究。

The Mesoproterozoic rift zones in the North China Craton include the Xiong'er, Yanliao and Zhaertai-Bayan Obo-Huade rift zones from south to north. The Xiong'er Group is featured by the major volcanism at 1780~1750Ma, above which the Wufoshan, Ruyang and Guandaokou groups were formed in a passive continental margin. The Yanliao rift zone includes the Changcheng, Jixian and Qingbaikou systems. The Tuanshanzi and Dahongyu formations of the Changcheng system have volcanic rocks at ca.1640Ma and 1626~1622Ma, respectively. The tuffs in the Gaoyuzhuang, Wumishan and Tieling formations of the Jixian system were formed at 1560Ma, 1485Ma and 1437Ma respectively, whereas the Xiamaling tuffs in the unnamed system have ages of 1366~1380Ma. In the Zhaertai-Bayan Obo-Huade rift zone, the Shujigou basalts and Agulugou felsic volcanics of the Zhaertai Group have ages of 1743Ma and ~810Ma, respectively. The Jianshan Formation of the Bayan Obo Group has mafic volcanics of 1728Ma and the Bilute tuffs of the Huade Group formed at 1515Ma. Besides the volcanisms in the rift zones, the Mesoproterozoic magmatism include three episodes of mafic dyke swarms (ca.1780Ma Taihang-Lüliang dyke swarm, ca.1730Ma Miyun dyke swarm and ca.1620Ma Taishan dyke swarm) and 1.76~1.65Ga anorogenic magmatism (anorthosite-rapakivi granite-A-type granite). In the Middle Mesoproterozoic, mafic sills (dykes), A-type granites and carbonate dykes develop in the northern margin of the North China Craton. The bimodal magmatism suggests that the northern margin of North China Craton has experienced rifting in the Middle Mesoproterozoic, which are related with final breakup of the Columbia Supercontinent and formation of the giant Bayan Obo REE-Nb-Fe deposit. The two rift zones in the northern North China Craton have similar stratigraphic sequences and formation ages. The Middle Mesoproterozoic anorogenic magmatism can be compared with those in other cratons and suggests that the North China Craton is involved in the final breakup of the Columbia Supercontinent. Paleomagnetic data indicate that the Siberia, Laurentia, Baltica, Amazion and North China cratons are connected together in the Columbia Supercontinent, and the rift-related magmatic rocks in the northern margin suggest that it connected with another craton. However, whether the Xiong'er volcanics in the southern margin of the North China Craton formed in a continental rift or active continental margin is important about whether it was connected with another craton or faced an ocean, which need further studies.